When a silver halide photographic material is exposed and then color developed, a color image is formed by the reaction of an aromatic primary amine developing agent as oxidized with the silver halide and a dye-forming coupler.
In color image formation, a subtractive color process is often used, in which complementary yellow, magenta and cyan color images are formed for reproduction of blue, green and red colors, respectively.
As yellow couplers, phenoxy group-releasable compounds are disclosed in U.S. Pat. Nos. 3,408,194 and 3,933,501; imido group-releasable compounds in U.S. Pat. Nos. 4,022,620, 4,057,432, 4,269,936 and 4,404,274; and heterocyclic group-releasable compounds in U.S. Pat. Nos. 4,046,575 and 4,326,024. Using these couplers, increases in coloring rate and fastness of color images formed are still desired.
In order to improve the fastness of the color images formed from these yellow couplers, U.S. Pat. No. 4,268,593 has proposed hindered amine compounds.
However, as compared with remarkable progress in the improvement of the fastness of magenta color images and cyan color images, the fastness of yellow color images is insufficient, and still remains at a low level. Accordingly, the improvement of the fastness of cyan color images is strongly desired in this technical field.
In color photographs, it is desired that all of the yellow, magenta and cyan color images be uniformly fast to light, heat and wet heat, and that the three colors be at the same level. The present inventors have earnestly sought compounds for improving the fastness of color images formed from yellow couplers.
The epoxy compounds described in U.S. Pat. No. 4,239,851 are known to improve the fastness of cyan color images against heat and wet heat; and the epoxy compounds described in U.S. Pat. No. 4,540,657 are known to reduce the yellow stain which would result from decomposition of magenta couplers. The latter U.S. Patent further mentions that the color images from aryloxy group-releasable yellow couplers could have improved fastness to light and heat, but this effect remains insufficient. JP-A-62-75450 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") discloses cyclic ether compounds for reducing stains formed by processing with particular stable processing solutions. The present inventors have found that these compounds are effective for improving the fastness of the yellow color images, in particular in the dark under humid conditions, but the improvement in antifading properties in the light remained insufficient.
In the technical field of dispersing photographic oil-soluble compounds, it is known to disperse the compounds in oil-soluble homopolymers or copolymers, for example, as described in U.S. Pat. Nos. 3,619,195, 4,201,589 and 4,120,725.
The present inventors have now found that by incorporating a yellow coupler in a photographic material together with a water-insoluble but organic solvent-soluble polymer and an epoxy compound, not only the antifading properties of the image under wet heat is improved, but also the antifading properties thereof in light is surprisingly improved.